Microsoft Windows 10 KB5001330 causes frame rates to plummet, screen flickering and BSODs
It could also causes potentially loss of user files, DNS issues and boot-looping on rare systems.
For now it is best to uninstall KB5001330 for ver. 2004 and 20H1 builds and KB5001337 if you're running a build older than 2004.
Until Microsoft have a solution for this.
Remember to Pause Windows update for a while - before uninstall KB5001330.
Hopefully in a couple of Weeks Microsoft has a solution and then activate Windows update again.
See the following articles:
Tom's Hardware: Latest Windows 10 Update Causes Frame Rates to Plummet and BSODs
Windows Central: How to uninstall update KB5001330 to fix issues on Windows 10
Windows latest: KB5001330 is now causing trouble for more Windows 10 users
Microsoft: KB5001330 known issues among several- lower than expected performance in games after installing this update.
Best regards from Sweden
[Edit] Updated with a Microsoft link and corrected some spelling.